In fact the file at that link is part of the DMD library but it's part of a repository that contains a whole pile of libraries, rather than just one as you might expect. You can download a zip of the entire repository, just as you do with any other GitHub repository by navigating to the root page of the repository, clicking the "Clone or download" button, then "Download ZIP". However, due to the DMD library not being in the root of the repository, you will not be able to use Sketch > Include Library > Add .ZIP Library to install it. Instead you would need to do a manual installation of the DMD library, following these instructions:https://www.arduino.cc/en/Guide/Libraries#toc5

But first, note that file is not in a fonts subfolder as the include statement expects. This makes it seem likely this isn't the library the sketch in your book was written for. Maybe it can be made to work but it would be good to investigate further before resorting to shoehorning this file into the project.

... note that file is not in a fonts subfolder as the include statement expects. This makes it seem likely this isn't the library the sketch in your book was written for. Maybe it can be made to work but it would be good to investigate further before resorting to shoehorning this file into the project.

... the file at that link is part of the DMD library but it's part of a repository that contains a whole pile of libraries, rather than just one as you might expect. You can download a zip of the entire repository, just as you do with any other GitHub repository by navigating to the root page of the repository, clicking the "Clone or download" button, then "Download ZIP".

Here's the essential clue. In order to include a file in the subfolder (fonts in this case) of a library you must first include a file in the primary source folder, otherwise the Arduino IDE will not find the file in the subfolder. So now we know that the library contains a file named glcd.h, a subfolder named fonts that contains a file named SystemFont5x7.h.

This library is no longer being maintained by the authors and has not been updated since December 2011. This library does not work with newer Arduino IDEs like the latest 1.0.x releases as well as 1.6.0 IDE and beyond since the newer IDEs use updated AVR gcc tools and GLCDv3 library uses code which is not compatible with the newer AVR gcc tools.

If you are ok with a GPL 3.0 licensed library (your project is open source) openGLCD is an alternative which is compatible with GLCDv3 and is being maintained.

That library does contain a fonts folder with the SystemFont5x7.h. I notice in the wiki is mentioned that library can be configured for GLCDv3 library compatibility mode so it may be quite simple to use your code with the newer library.

This is the problem with books. The just can't keep up with the rapidly changing world of technology. If the book doesn't at least give a URL where you can find the glcd library that's not a good sign of quality work.

I already explained this to you. You won't see the button when you're in a subpage of the repository. You need to navigate up to the root page of the repository. The easiest way to do that is to click the repository (not user) name in the top left corner of the screen. For example in the first of your links you would click on "Basic". Then voila, you have a "Clone or download" button.

I don't know. I've never used the library. You might want to look into this compatibility mode mentioned in the wiki:https://bitbucket.org/bperrybap/openglcd/wiki/You could also just use the documentation and the example sketches that come with the library to start from scratch.

You could also just use the documentation and the example sketches that come with the library to start from scratch.

I really admire your optimism.

That's a little like expecting my four-year-old granddaughter to understand the WA Occupational Safety and Health Act 1982 - and I've worked with that for years and still don't claim to understand it!

That's why people like me, thrashing around trying to get to grips with microprocessors and all the goes with them, come to this forum. We are hoping that you folk who do understand such things will help us along the painful road towards understanding. We can only hope that it is not too much of a pain for you folks - and I am sure that I am not the only one who appreciates your patience.

"Answers are easy; it's asking the right questions which is hard." The Doctor (Dr Who: The Face of Evil (1977))